CVE-2020-13485: Verbb/knock knock Knock Knock Plugin IP Whitelist Vulnerability

CRITICAL
Advisory Identifier: GHSA-wxvr-qqm7-6h65
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CVSS 9.1
CWE-697
Published
Advisory Summary

CVE-2020-13485 is a CRITICAL (CVSS 9.1) knock knock plugin ip whitelist vulnerability (CWE-697: Incorrect Comparison) affecting Verbb/knock knock libraries in the Packagist ecosystem. The issue involves knock knock plugin ip whitelist bypass via an x-forwarded-for http header. Remediation is available by upgrading affected packages to version 1.2.8.

CVE-2020-13485 at a Glance

CVE Identifier CVE-2020-13485
GHSA Identifier GHSA-wxvr-qqm7-6h65
Severity CRITICAL
CVSS v3.1 Base Score 9.1
CWE Classification CWE-697: Incorrect Comparison
Affected Product Verbb/knock knock
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 9.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2020-13485

To remediate this vulnerability, upgrade all affected Verbb/knock knock dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

verbb/knock-knock fixed: 1.2.8 
Upgrade verbb/knock-knock to 1.2.8
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for verbb/knock-knock

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-13485, inspect your project dependencies for Verbb/knock knock:

inspect dependencies for verbb/knock-knock

Analyze the terminal output to locate any version of Verbb/knock knock in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.2.8), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-697: Incorrect Comparison, where the product compares two entities in a security-relevant context, but the comparison is incorrect. In Verbb/knock knock, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The Knock Knock plugin before 1.2.8 for Craft CMS allows IP Whitelist bypass via an X-Forwarded-For HTTP header.

CVE-2020-13485 Affected Verbb/knock knock Versions

1 component(s)
Fixed Versions:
1.2.8
Product / Package Ecosystem Affected Versions Fixed Version
verbb/knock-knock
 Packagist
< 1.2.8
1.2.8

References

NVD — CVE-2020-13485 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-13485
Verbb/knock knock Source Repository REPOSITORY
https://github.com/verbb/knock-knock
Verbb/knock knock Source Repository REPOSITORY
https://github.com/verbb/knock-knock/blob/craft-3/CHANGELOG.md
Verbb/knock knock Security Information SECURITY
https://limpidsecurity.pl/security-advisories/1/knock-knock-plugin-for-craft-cms

Frequently Asked Questions

What is CVE-2020-13485?
CVE-2020-13485 is a security vulnerability in Verbb/knock knock involving Knock Knock plugin IP Whitelist bypass via an X-Forwarded-For HTTP header under CWE-697: Incorrect Comparison.
Which Verbb/knock knock versions are affected?
Affected versions include releases prior to 1.2.8 across affected packages: verbb/knock-knock.
What version fixes CVE-2020-13485?
Upgrading to 1.2.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is verbb/knock-knock affected?
Yes, verbb/knock-knock is affected in releases prior to 1.2.8. Upgrade your dependency to 1.2.8 or later.
What is the CVSS score of CVE-2020-13485?
CVE-2020-13485 has a CVSS v3.1 base score of 9.1 (CRITICAL) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2020-13485?
CVE-2020-13485 is classified under CWE-697: Incorrect Comparison (The product compares two entities in a security-relevant context, but the comparison is incorrect.).
How can I check Packagist dependencies for CVE-2020-13485?
Run the dependency tree command: 'inspect dependencies for verbb/knock-knock'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-wxvr-qqm7-6h65",
  "modified" : "2024-04-24T17:46:47Z",
  "published" : "2022-05-24T17:18:42Z",
  "aliases" : [ "CVE-2020-13485" ],
  "summary" : "Knock Knock plugin IP Whitelist bypass via an X-Forwarded-For HTTP header",
  "details" : "The Knock Knock plugin before 1.2.8 for Craft CMS allows IP Whitelist bypass via an X-Forwarded-For HTTP header.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "verbb/knock-knock"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.2.8"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-13485"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/verbb/knock-knock"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/verbb/knock-knock/blob/craft-3/CHANGELOG.md"
  }, {
    "type" : "WEB",
    "url" : "https://limpidsecurity.pl/security-advisories/1/knock-knock-plugin-for-craft-cms"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-697" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-04-24T17:46:47Z",
    "nvd_published_at" : "2020-05-25T23:15:00Z"
  }
}